Electric control device

ABSTRACT

An electric control device for mounting on a control panel which device includes an assembly of an electrically insulating housing and of a mounting bracket in which assembly a contact carrier structure is movable between open and closed positions relative to a stationary contact structure by electromagnetic means against biasing means for holding the contact carrier structure in one of the positions, and the assembly having means for readily detachably mounting the housing on the bracket to facilitate access to the interior of the assembly without removal of the bracket from the mounting panel.

United States Patent [1 1 Grunert et a1.

[ 1 ELECTRIC CONTROL DEVICE [75] Inventors: Kurt A. Grunert; John J. Bauer, Jr.,

both of Beaver, Pa.

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa. 221 Filedi Jan. 17, 1972 [21] Appl. No.2 218,103

[52] U.S. Cl. 335/132, 200/168 [51] Int. Cl. 110111 50/02 [58] Field of Search 335/132, 131, 126, 335/202; 200/168; 317/119 [56] References Cited UNlTED STATES PATENTS 3,215,800 11/1965 Hurter et a]. 200/168 C 3,102,935 9/1963 .Christeler 335/202 3,202,785 8/1965 .lelley 335/132 Swindler et al. 335/132 July 24, 1973 3,651,437 3/1972 Kiyoshi 335/131 2,665,353 1/1954 Popp ZOO/168 C Primary Examiner-Harold Broome Attorney-A. T. Stratton. l.ee P. Johns et al.

[57] ABSTRACT An electric control device for mounting on a control panel which device includes an assembly of an electrically insulating housing and of a mounting bracket in which assembly a contact carrier structure is movable between open and closed positions relative to a stationary contact structure by electromagnetic means against biasing means for holding the contact carrier structure in one of the positions, and the assembly having means for readily detachably mounting the housing on the bracket to facilitate access to the interior of the assembly without removal of the bracket from the mounting panel.

7 Claims, 4 Drawing Figures ELECTRIC CONTROL nsvrcu CROSS REFERENCE TO RELATED APPLICATION This invention is related to the invention disclosed in the application of Kurt A. Grunert, Thomas Rehm, and Charles R. Paton, Ser. No. 218,104, filed Jan. 17, 1972.

BACKGROUND OF THE INVENTION 1. Field 'of the Invention This invention relates to electric control devices and more particularly to electric control devices such, for example, as contactors or relays that are operated by electromagnetic: operating means.

2. Description of the Prior Art In the electric control art compact control devices adapted for mounting on panel boards and control panels are well known. One type of electric control device is that disclosed in US. Pat. No. 3,296,567, issued .Ian. 3, 1967, entitled Electric Control Device to J. P. Conner and Kurt A. 'Grunert.

An inherent problem with most electric control devices such as two-pole contactor that are mounted on control panels is the difficulty of changing the device to adapt to varying conditions of electric supply. For example, the coil of a commercially available contactor may be useful only with 24 voltage current where 120 voltage supply is available. Most of the prior known contactors have been so constructed that they must be completely removed from the control panel in order to change a coil to a different voltage requirement. That procedure for changing the coil has been cumbersome and time-consuming and has therefore created a need for a contactor which, after installation on a mounting,

panel, is readily adapted to a coil change without complete removal from the mounting panel in order to disassemble the entire contactor from the bottom end. It is a salient feature of this invention that the assembly of the insulating housing, the stationary contact structure, the movable contact carrier structure, the biasing means, and the armature comprise a unitary assembly removable as a unit from the mounting bracket.

Associated with the foregoing have been problems of assembly and production costs.

SUMMARY OF THE INVENTION movable between open and closed positions relative to the. stationary contact structure. Biasing means are provided for holding the movable contact carrier structure in one of the operating positions, such as the open position. Electromagnetic means are provided for actuating the contact carrier structure to the other operating position, such as the closed position and comprises a magnetic coil, an armature, and the mounting bracket which has a U-shape configuration and is adapted to support the magnetic coil and which serves as a ferromagnetic path for the electromagnetic field generated by the. coil when actuated. Finally, the assembly. comprises detachable mounting means including an elastically deformable structure for mounting the housing on 2 the bracket for enabling easy access to the interior of the assembly without removal "of the bracket from a mounting panel.

A salient feature of this invention is the provision of easily detachable mounting means for separating the electrically insulating housing from the mounting bracket with a minimum of effort and without removing the bracket from a mounting panel in order to facilitate quick access to the interior of the assembly for any purpose such as replacement of a coil. The detachable mounting means also thereby facilitates reassembly of the housing and the mounting brackets with a minimum of effort and time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of an electric control device or contactor in accordance with the principles of this invention,

FIG. 2 is a plan view of the device shown in FIG. I; FIG. 3 is a vertical sectional view taken on the line III-III of FIG. 2; and

FIG. 4 is a vertical sectional view taken on the line IVIV of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, an electric control device or contactor is generally indicated at 10 and it comprises a housing 12 and a mounting bracket 14. In addition, as shown in FIG. 4, the device 10 also includes a movable contact carrier structure 16 and electromagnetic means 18 for actuating the contact carrier structure in a manner to be described hereinbelow.

The housing 12 is composed of an electrically insulating or dielectric material such as a phenolic resin. The contactor 10 is a multi-pole type such as a two-pole contactor. The housing 12 is a shell-like member having a top wall 20, opposite side walls 22 and 24, and opposite end walls 26 and 28. In addition, the housing includes a pair of spaced partitions 30 and 32 (FIG. 2) which extend between the end walls 26 and 28. As shown more particularly in FIG. 2, a pair of spaced walls 34 and 36 extend downwardly from the top wall 20 between the partitions 30 and 32. A wall 38 extends downwardly from the top wall 20 between the walls 34 and 36 and parallel to the partitions 30 and 32. The wall 38 has a lower end 40 which serves as a stop member for limiting upward movement of the movable contact carrier structure 16.

As shown in FIGS. 1, 2 and 3, four stationary contact structures 42, 44, 46, and 48 are providedin pairs at opposite end walls 26 and 28. As shown more particularly for thecontact structures 42 and 46, said structures are disposed between similar spaced pairs of partitions S0 and 52 extending outwardly from the end walls 26 and 28. Each stationary contact structure 42-48 comprises a U-shaped conducting strap 54 (FIG. 3), a terminal screw 56, stationary contacts 58, and wire connecting terminals 60. The conducting strap 54 has an upper portion extending through an opening 62 on the end wall 28 and is disposed in a chamber 64 between the side wall 24 and the partition 32. A similar chamber 64 is disposed between the side wall 22 and the partition 30. Both chambers 64 extend between the end walls 26 and 28. The stationary contacts 58 are in vertical alignment with and in a path of travel of movable contacts 66. The terminal screw 56 secures the conducting strap 54 in place on a projecting portion 68 of the wall 28. The wire-connecting terminals 60 extend outwardly to facilitate connection of a lead wire thereto in a conventional manner.

As shown in the drawings, the top wall 20 is provided with a pair of spaced openings 70 and 72 which communicate separately with the chambers 54. Likewise, similar openings 74 are provided in the top wall each of which is in substantial alignment with the path of travel of a corresponding movable contact 66.

As shown in FIGS. 1 and 2, a vertically extending slot 76 is provided between the partitions 52 which slot is aligned with a screw-receiving notch 78. One notch 78 is preferably disposed at each end of the mounting bracket 14 whereby the bracket may be attached by screws 80 (one of which is shown in FIG. 1) to a mounting panel 82. By aligning the slot 76 with a corresponding notch 78 the shank of a screwdriver may be disposed in the slot for setting screws 80 in place.

Finally, the housing 12 is provided with four prongreceiving openings 84 near opposite corners of the device. The openings 84 cooperate with prongs 86 for securing the housing 20 to the mounting bracket 14 in a manner to be described below.

The mounting bracket 14 is a U-shaped member having upturned legs 88 and 90 and an intermediate base 92. The bracket is composed of a ferromagnetic material such as low carbon steel, for example, cold rolled steel plate. The mounting bracket 14 serves as a magnetic field path for an electromagnetic field generated by a magnetic coil 94 which is part of the electromagnetic means 18.

In addition to providing means for mounting the con tactor on the mounting panel 82 (FIG. 1) as well as serving as a magnet member for maintaining the electromagnetic force of the coil 94, the mounting bracket includes means for attaching the housing on the upper end of the bracket. For that purpose, the bracket has upwardly extending projections 96 disposed in pairs extending from opposite ends of the legs 88 and 90, one of which is shown in FIG. 3. Each projection extends through a corresponding prong-receiving opening 84 in the housing 12 and each projection includes one prong 86 at the upper end thereof which extends above a corresponding horizontal surface 98 when lower surfaces 100 are seated in abuttment with support surfaces 102 and upper ends of the legs 88 and 90 of the bracket 14.

Inasmuch as in the bracket 14 is composed of a low carbon steel, the upper end portions or prongs 86 are elastically deformable and may be bent slightly over the surfaces 98 in a manner shown in FIGS. 1 and 3 and thereby secure the housing 12 in place on the bracket 14. Conversely, the prongs 86 may be returned to upright positions 86a, as shown in FIG. 3, whereby the prongs are in alignment with the respective openings 84 to enable the removal of the housing from the bracket 14 for any purpose such as maintenance. Inasmuch as the bracket 14 is composed of a low carbon steel, it is readily deformable within broad elastic limits of the material so that the prongs 86 may be repeatedly bent between the upright and angled positions without breaking the prongs from the projections 96. Thus, the combination of the prongs 86 and the prong-receiving openings 84 comprise means for readily detachably mounting the housing 12 on the bracket 14.

In addition to the foregoing, the legs 88 and 90 include upper end surfaces 104 and 106, respectivley,

which extend between the pairs of projections 96 on each leg.

Finally, a magnetic core 108 is centrally mounted on the base 92 of the bracket 14. The core 108 is a laminated assembly of low carbon or ferromagnetic steel sheet-like members and is fixedly attached to the base 92 in a well-known manner such as by staking.

The movable contact carrier structure 16 comprises a generally U-shaped contact carrier member 112, a magnetic armature 114, and separate bridging contact members 116. The contact carrier member 112 is composed of an electrically insulating material such as a phenolic resin. As shown in the drawings, the contact carrier member 112 is movably mounted in the housing 12 with upper ends of the U-legs extending into the openings and 72 of the housing. One U-leg portion of the U-shaped member 112 is disposed in one chamber 64 and the other portion is disposed in the other chamber 64 with an intermediate portion or crossbar 118 (FIG. 4) extending therebetween and under the partitions 30 and 32. In addition, each U-leg member 112 is provided with a projection or ear 120 (FIGS. 1, 2 and 4) which extends outwardly in opposite directions of each other and through vertical slots or openings 122 and of opposite side walls 22 and 24.

As shown more particularly in FIGS. 1 and 4, each ear 120 is disposed at the upper end of a coil spring 124, the lower end of which spring is supported on the surface 98. The springs 124 hold the contact carrier member 112 in the upper operating position. In FIG. 4, each ear 120 is provided with a downwardly extending projection or pin-like portion 126 in order to retain each spring 124 in place. The lower end 40 of the wall 38 serves as a stop for the upper limit of travel of the contact carrier member 112 and for that purpose, the member 112 includes an upright portion 128 extending from the crossbar 118 and disposed between the U-legs of the member 112. It is pointed out, however, that a clearance space 130 exists between the lower end 40 of the wall 38 and the upper end of the upright portion 128 which space varies in accordance with the upper and lower operating positions of the contact carrier member 112.

As indicated above, the contact carrier member 112 also includes a pair of bridging contact members 116 which extend between corresponding pairs of separated stationary contacts 58. The movable contacts 66 are secured to opposite ends of the bridging contact members 116. The bridging contact members 116 are electrical conductors preferably composed of metal and as shown in FIGS. 3 and 4. One member 116 extends through a window 132, one window being provided in the upper end of each leg of the contact carrier member 112. In each of the windows, a separate compression spring 134 holds the associated bridging contact member 116 in place to provide for resilient contact engagement between the corresponding movable contacts 66 and stationary contacts 58 in a manner similar to that set forth in the above mentioned U.S. Pat. No. 3,296,567.

The contact carrier member 112 also includes the magnetic armature 114 which extends between the upper end surfaces 104 and 106 above the mounting brackets 14 for the purpose of completing the loop of the electromagnetic field when the magnetic coil 94 is actuated. The armature l 14 is secured to the lower end surface of the contact carrier member 112 by an inverted U-shaped clip 136 (FIG. 3) which clip includes an intermediate portion 138, a pair of downturned similar leg members 140, and an outtumed flange 142 at the lower end of each legmember. Each flange is secured to the magnetic armature 114 by suitable means such as a rivet 144. The intermediate portion 138 extends across the upper end of the upright portion 128 through the clearance space 130 and the leg members 140 are in snug-fitting surface-to-surface contact with opposite sides of the upright portion 128, thereby serving as bearings between said portion and the partition 30 and 32 of the housing. Thus, the clip 136 serves a three-fold function of (l) acting as a bearing therebetween the contact carrier member 1 12 and the housing, (2) tieing the armature 114 to the crossbar 118, and (3) enabling self-alignment of the armature with the magnetic core and the upper ends of the surfaces 104 and 106 of the mounting bracket.

In addition, the intermediate portion 138 is spaced above the upper end of the upright portion 128 by a slight clearance 146.'A pair of similar projections 148 extend downwardly from the lower surface of the crossbar 118 and into corresponding openings 150 in a loosely fitting manner. Accordingly, the combination of the clearance 146 and the loose fit of the projection 148 in the openi ngs 150 contribute to the self-aligning function of the armature 114 when the magnetic coil 94 is energized or actuated, thereby permitting less precise tolerances between the several associated parts and quieter operation of the armature as it moves into contact with the mounting bracket 14 when the mag netic coil is actuated. The position of the armature 114 is indicated by the broken-line position 1140 in FIG. 4. The advantage of the use of the U-shaped clip 136 for mounting the armature on the crossbar as well as of the loose-fitting connection between the clip, the crossbar, and the armature 114 is the avoidance of potential binding between the cross-bar and the housing. The leg members 140 ,of the U-shaped clip 136 provides smooth metal surface between the electrically insulating'material of the crossbar and the housing which prevents the disadvantage of sluggish movement of the contact in such a degree as to prevent proper switching operation which disadvantage was inherent in prior art constructions. I

Accordingly, the electric control device for contactor of the present invention satisfies certain problems which were extant in devices of prior art construction including means for readily detaching the insulating housing from the mounting bracket for facilitating access to the interior valve the device without completely removing the mounting bracket from a mounting panel, and including the incorporation of structural features to avoid potential binding between the crossbar and the housing which in turn resulted in the prevention of proper switching in some prior art devices.

What is claimed is:

1. An electric control device for use on a mounting panel comprising an assembly of an electrically insulating housing and of a mounting bracket for fixedly attaching the assembly to a mounting panel, the housing comprising a stationary contact structure, a movable contact carrier structure within the housing and movable between open and closed positions relative to the stationary contact structure, biasing means for holding the movable contact carrier structure in one of the positions, electromagnetic means for actuating the contact carrier structure to the other of the positions and comprising a magnetic coil and an armature, the magnetic coil being mounted on.one of the movable contact carrier structure and the mounting bracket, the armature being mounted on the other of the movable contact carrier structure and the mounting bracket, means for readily detachably mounting the housing on the bracket for enabling easy access to the interior of the assembly without removal of the bracket from a mounting panel, said detachable mounting means com prising an elastically deformable prong on the bracket and a surface on the housing and the prong being bendable between locked and unlocked positions, the prong extending over the surface in the locked position, the detachable mounting means comprising the bracket and the housing having mutually interfitting portions and comprising a prong-receiving aperture in the housing.

2. The device of claim 1 wherein the mounting bracket comprises a U-shaped ferromagnetic member having an intermediate base and two spaced upturned end portions, the electromagnetic means also comprises a magnetic core mounted on the intermediate base, and the magnetic coil is disposed in the bracket and around the core. r

3. The device of claim 2 wherein the armature comprises plate-like ferromagnetic member extending between and movable between contacting and noncontacting positions relative to the two spaced upturned end portions.

4. The device of claim 3 wherein the movable contac carrier structure includes a crossbar extending at least a portion of the distance between two spaced upturned end portions, and means for mounting the plate-like ferromagnetic member on the crossbar and between the crossbar and the upturned end portions.

the crossbar and adjacent housing surfaces.

in a s e a 

1. An electric control device for use on a mounting panel comprising an assembly of an electrically insulating housing and of a mounting bracket for fixedly attaching the assembly to a mounting panel, the housing comprising a stationary contact structure, a movable contact carrier structure within the housing and movable between open and closed positions relative to the stationary contact structure, biasing means for holding the movable contact carrier structure in one of the positions, electromagnetic means for actuating the contact carrier structure to the other of the positions and comprising a magnetic coil and an armature, the magnetic coil being mounted on one of the movable contact carrier structure and the mounting bracket, the armature being mounted on the other of the movable contact carrier structure and the mounting bracket, means for readily detachably mounting the housing on the bracket for enabling easy access to the interior of the assembly without removal of the bracket from a mounting panel, said detachable mounting means comprising an elastically deformable prong on the bracket and a surface on the housing and the prong being bendable between locked and unlocked positions, the prong extending over the surface in the locked position, the detachable mounting means comprising the bracket and the housing having mutually interfitting portions and comprising a prong-receiving aperture in the housing.
 2. The device of claim 1 wherein the mounting bracket comprises a U-shaped ferromagnetic member having an intermediate base and two spaced upturned end portions, the electromagnetic means also comprises a magnetic core mounted on the intermediate base, and the magnetic coil is disposed in the bracket and around the core.
 3. The device of claim 2 wherein the armature comprises plate-like ferromagnetic member extending between and movable between contacting and non-contacting positions relative to the two spaced upturned end portions.
 4. The device of claim 3 wherein the movable contact carrier structure includes a crossbar extending at least a portion of the distance between two spaced upturned end portions, and means for mounting the plate-like ferromagnetic member on the crossbar and between the crossbar and the upturned end portions.
 5. The device of claim 3 in which the means for mounting the plate-like member on the crossbar provides for loose mounting therebetween.
 6. The device of claim 5 in which the mounting means comprises a clip between the crossbar and the plate-like member.
 7. The device of claim 6 in which the clip is a U-shaped member have leg members disposed between the crossbar and adjacent housing surfaces. 